bio exam 3 chap 8-10

cellular respiration equation

glucose+oxygen-→ carbon dioxide+water+energy

32

number of ATP molecules produced during cellular respiration

glycolysis

breaks glucose (C6) into 2 pyruvate (C3), located in cytoplasm

citric acid cycle

breaks pyruvate into carbon dioxide, supplies next stage with electrons, located in mitochondria

oxidative phosphorylation

electrons shuttled through ETC, ATP is generated in association with chemiosmosis, located in inner mitochondrial membrane

steps of glycolysis

1-3) fuel molecule is energized using ATP 4) 6C intermediate splits into 2 3C intermediates 5) redox reaction generates NADH 6-9) ATP and pyruvate are produced (1-4 is energy investment, 5-9 is energy payoff)

products of glycolysis

2 pyruvate, 2NADH, 2 net ATP (4ATP/2ADP), 2 water molecules leave

steps of citric acid cycle

1) acetyl CoA brings 2 carbons into cycle 2-3) NADH, ATP, CO2 are generated during redox reactions, 4-5) redox reactions generate FADH2 and NADH

products of citric acid cycle

3NADH+ 3H+, FADH2, ATP, 2CO2 leave cycle, oxaloacetate

substrate level phosphorylation

transfer of P group from substrate to ADP to produce ATP

preparatory reaction

pyruvate is prepped in mitochondria to enter citric acid cycle (converted to acetyl CoA- 2 carbon molecule)

fermentation

breaks down glucose without oxygen

electron transport chain

pumps H+ ions, NAD+, FAD, releases water, ATP are made through ATP synthase (chemiosmosis), oxygen is the final acceptor

how cellular poisons affect cellular respiration

1) blocks ETC 2) inhibits ATP synthase 3) makes the membrane leak H+ ions

rotenone, cyanogenic glycosides

poisons that block ETC

antibiotic oligomycin

poisons that inhibit ATP synthase

dinitrophenol

poisons that make membrane leaky

lactic acid fermentation

muscle cells and certain bacteria, makes 2 ATP/2NADH

alcohol fermentation

baking and winemaking, makes CO2, NAD+

cell cycle

ordered set of stages that takes place between time eukaryotic cell divides and the time resulting daughter cells also divide

asexual reproduction

faster, don’t spend energy to find mate, little genetic diversity

interphase

growth and DNA synthesis occur when nucleus is not actively dividing, cells spend 90% of time here

chromatid

each double helix

histones

group of proteins found in chromatin

G1 phase

growth, increase in cytoplasm, DNA repair (# of organelles increases)

S phase

DNA replication and growth

G2 phase

growth, DNA repair, prep for division

G1 checkpoint

checks DNA for damage to send to S phase, if damaged goes to G0 state

G0

cells exit interphase, cells continue to perform normal processes with no prep for cell division, can reenter cycle if conditions become suitable for growth

p53

protein that stops cycle if DNA is impossible to repair

sister chromatids

formed during S phase, identical DNA molecules, joined at centromere

centromere

region of chromosomes microtubule spindles attach via kinetochore

G2 checkpoint

checks proper DNA replication to move to M

mitosis

division of nucleus

cytokinesis

division of cytoplasm

M checkpoint

checks chromosome alignment

apoptosis

programmed cell death, occurs if checkpoints detect errors

hair cell

example of cell that passes through G1 checkpoint

euchromatin

chromatin with lower level of compaction, accessible for transcription

heterochromatin

highly compact chromatin not accessible for transcription

prophase

formation of mitotic spindle, each centrosome has a pair of centrioles, chromosomes condense in nucleus, mitotic spindles elongate in cytoplasm

prometaphase

nuclear envelope disappears, spindle microtubules reach chromosomes, microtubules attach to centromeres of sister chromatids at kinetochore, chromosomes moved to center of cell

metaphase

spindle is fully formed, chromosomes align at cell equator (plate), kinetochores are facing opposite poles of spindle

anaphase

chromatids are separate and move to opposite poles, motor proteins move chromosomes along spindle microtubules, microtubules attached to kinetochore shorten, cell elongates

telophase

cell continues to elongate, nuclear membrane forms at each pole, chromosomes unfold and disperse, spindle microtubules disassemble

cytokinesis in animal cells

cleavage furrow and contractile ring of actin and myosin microfilaments (pinches cell in 2) formed

cytokinesis in plant cells

vesicles from Golgi apparatus form cell plate of cellulose and proteins, cell plate grows outward to reach edges which divides content into 2 cells each with plasma membrane and cell wall

protooncogenes

promote cell cycle and prevent apoptosis, caused by mutations to oncogenes

tumor suppressor genes

inhibit cell cycle, mutations inactivate genes which causes uncontrolled division

somatic cells

body cells, pairs of homologous chromosomes, one from each parent

homologous chromosomes

same length, centromere position, gene locations/locus (different versions of a gene at same locus)

autosomes

all chromosomes that aren’t sex chromosomes (X/Y)

meiosis

reduces number of chromosomes in half

meiosis I

separates homologous chromosomes, chromosome # cut in half

meiosis II

separates sister chromatids, chromosome # stays the same

prophase I

chromosomes are compacted, synapsis occurs (homologous chromosomes attached by proteins), tetrads form (4 chromatids), non-sister chromosomes exchange genetic material (crossing over), spindle fibers form

metaphase I

tetrads align at cell equator (plate), microtubules attach to kinetochore

anaphase I

homologous pairs separate and move towards opposite poles

telophase I

chromosomes move to poles with haploid set at each pole (linked sister chromatids, some form nuclear membrane around chromosomes), cytokinesis

prophase II

chromosomes coil and compact, spindle apparatus forms and attaches to kinetochores of each sister chromatid

metaphase II

duplicated chromosomes align at metaphase plate, kinetochores of sister chromatids face opposite poles

anaphase II

centromeres of sister chromatids separate, chromatids move to opposite poles

telophase II

chromosomes reach poles of cell, nuclear envelope forms, cytokinesis, 4 haploid daughter cells

why offspring aren’t identical to parents

1) Independent orientation of chromosomes at metaphase I 2) random fertilization 3) different alleles on homologous genes 4) crossing over

karyotype

picture of chromosomes dividing in cell

nondisjunction

failure of chromosomes or chromatids to separate during meiosis

aneuploidy

change in chromosome # resulting from nondisjunction during meiosis

klinefelter syndrome

XXY male, most common,

turner syndrome

X0 female, all or part of one sex chromosome is absent

deletion

end of chromosome breaks off

duplication

presences of chromosome segregation more than once in the same chromosome

inversion

segment of chromosome is turned 180 degrees

translocation

movement of chromosome segment from one chromosome to another non homologous chromosome (reciprocal if there is swapping between chromosomes)